Hard lead alloys.



' No Drawing.

-To all whom it may concern:

FRANCIS G. FRARY, OF MINNEAPOLIS, AND STERLING N. TEMPLE, OF ST. PAUL, MINNESOTA; SAID TEMPLE ASSIGNOR OF ONE-SIXTH OF THE WHOLE RIGHT TO SAID FRARY.

Be it known that we, FRANCIS CF ARY and STERLING N. TEMPLE, citizens of the United States, residing FRANCIS C. FRARY,

at the city of Minneapolis, in the county of Hennepin and State of Minnesota, and STERLING N. TEMPLE at St. Paul, in the county of 'Ramsey and State of Minnesota, have invented certain new and useful Improvements in Hard Lead Alloys; and We do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

Our invention has for its object to provide an improved metallic alloy having certain characteristics especially adapting it for use in the casting of type and similar articles in molds, and in the manufacture of bullets and other forms of ammunition.

In the manufacture of type metal, hardness and resistance to compression without cracking are necessary, ,and furthermore,

the metal employed must be of such charac ter that it will not contract on solidifying, but, on the contrary, will slightly expand and fill the mold in which it is cast. In the manufacture of ammunition, it is very de alloy. Furthermore, antimony, especially at the present time, is veryexpensive, as compared with lead, and because of the considerable amount thereof necessarily employed, makes the alloy expensive.

In carrying out our invention, we use a small quantity of metallic calcium in a main body of lead. We have also found that with a very small per cent., to-wit, less than two per cent. of metallic calcium in lead, the

alloy may be made as hard as where a much greater quantity of antimony is used. We have also found that the alloy containing a small amount of metallic calcium may be improved and made still harder by the use of a small amount of copper or a small amount of aluminum, or small amounts of Specification of Letters Patent.

Application filed July 26, 1915.

HARD LEAD ALLOYS.

Patented Nov. 2, 1915.

Serial No. 41,948.

both of the said hardening metals. Copper and aluminum are two examples of metals that are relatively hard, as compared with lead and which, in addition to the metallic calcium, may be used to great advantage in small proportions, in the alloy. The small amount of copper in the alloy also causes the same to be Very tough, and not have that brittleness which characterizes ordinary antimonial lead.

While we have sometimes used more than two per cent. of metallic calcium and somewhat more than one per cent. of copper, we have obtained the best results by the use of about one-half per cent. of metallic calcium and two tenths per cent. of copper.

As further examples of alloys made in ac cordance with our invention, the following two formulas are given: 1st. Ninety eight per cent. of lead, two per cent. of metallic calcium. 2nd. Ninety-six and one-half per cent. of lead, three per cent. antimony, three-tenths, per cent. of calcium and twotenths per cent. of copper.

All of these alloys have very high specific gravity, are hard and tough, and furthermore, will not contract, but will expand more or less as they cool and solidify. Commercial lead, as well as pure lead, is, in this specification, and in the claims, intended to be included and covered by the term lead.

It is a well known fact that commercial lead usually contains small quantities of copper, and some other materials not removed in the customary process of purification. Frequently, the commercial lead will contain as large an amount of copper as wouldbe desired in the 'alloy, and in this case, a further addition of copper would not, of course, be needed. An alloy that will not contract when solidifying, is desired for the manufacture of type, and most all forms of ammunition, but even'if the proportions of materials used were such that a slight contraction would take place, the alloy made in accordance with this invention would have the highly desired qualities ofhardness and toughnessand would have commercial value for a good many purposes.

What we claim is:

1. As a new article ofmanufacture, a metallic alloy having a main body of lead and containing a small amount of metallic calcium.

2. As a new article of manufacture, a me-' tallic alloy havin a main body ofl'ead and containing a smal amount of metallic calcium, and also a'small amount of hardening metal. 4

3. As a new article of manufacture, a metallic alloy-having a main body of lead and containing a small amount of metallic calcium, and'also a small amount of copper.

4. As a new article of manufacture, a metallic alloy havinga main body of lead and containing metallic calcium in an amount less than two per cent.

- 5. As a new article of manufacture, a metallic alloy having a main vbocly of lead and 15 containing metallic calcium in an amount less than""tw0 per cent., and also a small FRANCIS C. FRARY. STERLING N. TEMPLE.

Witnesses:

C; A. OLSON, F. D. MERCHANT. 

